Log barker



Aug. 23, 1966 v. E. KEENEY LOG BARKER Filed April 27, 1964 I11 INVENTOR. VADERON E. KEENEY BY q sq es QQM A fiarncy United States Patent 3,267,976 LOG BARKER Vaderon E. Keeney, Eugene, Oreg, assignor to Miller Redwood Company, Portland, 0reg., a corporation of California Filed Apr. 27, 1964, Ser. No. 362,655 9 Claims. (Cl. 144-208) This invention relates to improvements in a log barker, especially for handling large logs with stringy bark such as redwood, cedar and the like. The invention more particularly relates to a log supporting mechanism which supports and rotates the log for action by a rossing head.

Conventional rossing heads are satisfactory for removing stringy bark but conventional log supporting and turning mechanisms are unsatisfactory because the long strings of bark become so entwined in the mechanism that someone must be present almost constantly to clear out the bark and keep the mechanism operating. Whereas bark from most other large trees readily fractures and fragments into chunks and small pieces, and can be readily collected and disposed of by mechanical means, the stringy type of bark cannot be handled automatically by existing equipment.

As a result of this difliculty, it has been the practice to remove stringy type bark in the woods where it is wasted. Uses have been found for this type of bark, however, and it is becoming of increasing value. It is, therefore, desirable to bring the logs to the mill for barking quickly and efficiently by a routine machine operation, both to reduce the cost of barking and to make the bark conveniently available for commercial use. In order to do this it is necessary to provide new and improved barking apparatus.

The general object of the present invention is, therefore, to provide a log barker for handling stringy type bark and, more particularly, to provide an improved log supporting and turning mechanism which will not become fouled by this kind of bark. Another object is to provide an improved sup-porting and turning mechanism for handling extremely large and heavy logs.

In the present barker, the log supporting and turning mechanism comprises two trunnion wheel units supported only in end hearings to allow free flow of the bark from the log to a completely open space below the log which is available for suitable automatic disposal means such as a conveyor. The bearings at each end of the trunnion wheel units are mounted on walking beams which may be rocked by means of air or hydraulic cylinders to unload the logs in a lateral direction, thus eliminating the generally used unloading arms which obstruct the bark flow. The walking beam supports for the trunnion wheels are arranged to act as a cushion for impacts on the mechanism when large and ponderous logs are rolled into the trough of the trunnion wheels. This apparatus is designed to handle logs from small size up to ten feet in diameter.

The invention will be better understood and the foregoing and other objects and advantages will become apparent from the following detailed description of the preferred embodiment illustrated on the accompanying drawing. Various changes may be made, however, in the details of construction and arrangement of parts and certain features may be used without others, all such modifications within the scope of the appended claims being included in the invention. It is also to be understood that although the present apparatus is especially suited for handling large logs with stringy type bark, the invention is not limited to use with any particular kind of bark or species or size of tree.

In the drawing:

FIGURE 1 is a top plan view of an apparatus embodying the features of the invention;

FIGURE 2 is an end elevation view; and

FIGURE 3 is an enlarged cross sectional view showing the walking beam support for one end of the trunnion wheel units.

The present apparatus is mounted on an elevated deck frame 10 On posts 11 which are supported on a floor or foundation 12. Mounted on the deck frame at each end thereof is a bearing 15 for a walking beam trunnion 16 of a walking beam 20. The ends of the walking beams are equipped with bearings 21 for the end trunnions 22 of two parallel trunnion wheel units 24 and 25. These units have wheels 27 and 28 mounted at intervals along a pair of trunnion tubes 26 which are connected at their ends to the trunnions 22. The tubes 26 are preferably about half as large in diameter as the wheels 27 and 28 in order to provide suificient beam strength so that intermediate supports will not be necessary between the trunnions 22 at the opposite ends of the tubes.

In order to turn a log L in the trough of the trunnion wheels, the latter are rotated by a shaft 30 at one end of the deck frame 10 which shaft is coaxial with the walking beam trunnions 16. The outer end of shaft 30 is equipped with a sprocket wheel 31 to be driven by a chain from a reversible electric motor. The inner end of shaft 30 is equipped with a sprocket wheel 32 having a chain drive connection with a sprocket wheel 33 on the trunnion 22 of trunnion wheel unit 24. The opposite ends of the trunnion wheel units 24 and 25 carry sprocket wheels 34 and 35, respectively, the latter being driven by the former by means of chain 36.

Thus, the supporting wheels 27 and 28 are rotated to turn the log L under a conventional rotary rossing head for removing the bark. The rossing head 40 is mounted on a carriage 41 which runs on a track in a carriage way on the deck frame 10 alongside the trunnion wheel unit 25. The carriage is moved by a endless cable 45 which is trained around sheaves 46 at opposite ends of the deck frame 10. This movement is produced by suitable motive power applied to one of the sheaves 46. The carriage way extends beyond both ends of the trunnion wheel units in order to get the carriage out of the way in unloading a log. The carriage may be suspended from an overhead track, if desired.

iRossing head 40 is mounted on the outer end of an arm 47 which is pivotally connected at its other end at 48 on the carriage 41. The rossing head 40 is driven by an electric motor 51 mounted on arm 47. The rossing head is raised and lowered by a fluid pressure cylinder 52 having pivotal connection 53 with the arm 47. The lower end of piston rod 54 in this cylinder is pivotally connected to a pivot on carriage 41. Thus, the rossing head can swing in an are 55 about the pivot 48 to act on logs smaller than the one shown, the are 55 terminating at its lower end in the trough between the two trunnion wheel units.

Bark removed by the rossing head is free to fall through open spaces between the trunnion tubes 26 and open spaces 61 between the trunnion tubes and longitudinal deck frame members 62 and 63. These openings are directly above a large open space or pit 65 between the deck frame supporting legs 11. This allows ample space for a belt or other conveyor means to be arranged in the space 65 to carry away 'all the bark.

The infeed conveyor system is conventional, comprising a plurality of parallel horizontal skid rails carrying lugged conveyor chains 71. These chain conveyor elements are arranged alongside the respective trunnion wheels 27 and terminate at approximately the high points of these wheels, whereby an approaching log is rolled in- 3 to the trough between the wheels 27, 28, as shown in FIG- URE 2. The chains 71 are driven by an electric motor 72.

Similar skid rails 75 and lugged chains 76 are arranged on the opposite side of the deck frame It) at a lower level to carry away the barked logs. These oftabearing chains are driven by motor 77. When a log is to be discharged, the carriage 41 is moved to one end of the carriage tway clear of the trunnion wheels as shown in FIGURE 1.

Means are provided for supporting the log and rolling it across the carriage track. These means comprise sloping ramp ends 80 on the rails 75, bridge ramp sections 81 and ramp end sections 82 adjacent and overlapping the trunnion wheels 28. These ramp sections are all disposed in a common inclined plane. The ramp sections 81 are provided with a slot for the cable 45, and the carriage 41 is provided with a tunnel 83 to pass over the ramp sections 81. Ramp sections 82 are lower than the tops of trunnion wheels 28 in normal position to allow for the depression of trunnion wheel unit 25 in the unloading movement of walking beams 20, as will presently be described.

These ramp sections and the inner ends of infeed skid rails 70 slightly overhang the pit 6 and, with the trunnion wheel units, constitute the only obstructions in the way of bark falling to the pit 65. The projecting ends or tinfeed rails 71) are automatically kept clear of bark by the movements of the feed chains 71. Bark shreds hanging up on the ramp end sections 82 may be cleared by clockwise rotation of the trunnion wheels 28 as viewed in FIGURE 2. Rotation of the trunnion wheels in either direction keeps the trunnion wheel units clear of bark. Thus, all the projections on which bark might hang up are provided with eifective means to clear the bark away so that it does not remain and accumulate on these projections.

The unloading movement of walking beams is shown in broken lines in FIGURE 3, the top of depressed trunnion wheels 28 in bro-ken line position being approximately on a level with end ramp sections 82. The log is rolled over trunnion wheels 28 and onto the sloping ramp sections by the elevation of trunnion wheels 27 when the trunnion wheels 28 are lowered.

The walking beams 20 are tilted by a fluid pressure cylinder 85 at one end of the trunnion wheel units, The piston rod 86 in each cylinder is connected to a cross head 87 slidable on a vertical guide 88 anchored to a post 11. A pivotal link 89 extends from the cross head to a pivot 90 on an arm 91 on one end of an equalizing shaft 92. A pivotal link 93 extends from pivot 90' to one end of one of the walking beams 20. A similar arm 91 and link 93 connect the opposite end of shaft 92 with the other walking beam 20. Fluid pressure in the upper end of cylinder 85 normally holds the right ends of walking beams 20 down in horizontal position against resilient resting pads 94, as shown in solid lines in FIGURE 3.

When a log is rolled into the trough of trunnion wheels 27 and 28 by the infeed chains 71, it first rolls across the trunnion wheels 27 and brings its weight to bear on the pads 94. Then, as the log rolls over against trunnion Wheels 28, a downward impact is imposed on the left ends of the beams 20. This momentarily raises the piston rod 86 against the pressure in the upper end of cylinder 85 with a shock absorber action. In this way loading im pacts resulting from the movements of pondero-us logs are cushioned by the shock absorber action of cylinder 85 and the trunnion bearings and other parts are not subjected to the full stresses which such impacts would otherwise produce on non-yieldable supporting elements.

During a barking operation, walking beams 20 are held in horizontal position by fluid pressure in the upper end of cylinder 85 as previously mentioned, and drive shaft driven to rotate the trunnion wheels and turn the log. As the log turns, carriage 41 is pulled along its track by cable so that the rossing head 40 can act on all parts of the surface or" the log to completely remove the b-ark. The trunnion wheels may be rotated in either direction. As the log rotates, irregularities will produce impacts, first against one trunnion wheel unit and then against the other, and these impacts also are cushioned and absorber by the pads Q4 and the shock absorber action of cylinder whereby the whole apparatus is subjected to less vibration and wear and tear than in conventional flog turning mechanisms After the barking operation has been completed, carriage 41 is shifted beyond the end of the log, as shown in FIGURE 1, and the valves, such as solenoid valves 95, controlling cylinder 85 are shifted to raise the piston rod 86. This movement of walking beams 20, as shown in broken lines in FIGURE 3, depresses the trunnion wheels 23 to the approximate level of end ramp sections 82 and raises trunnion wheels 27 to roll the log down over the ramp sections 82, 81, 80, to the ofiabearing chains 76.

Valves 95 are shown close to the cylinder 85 as they would be for pneumatic operation. In such case, the cylinder must be a double air cushion cylinder which cushions on the extreme up stroke and also on the extreme down stroke. The desired cushion action can also be obtained with an incompressible fluid medium such as oil by providing air cushion chambers in the hydraulic lines as is well understood in the art.

Having now described my invention and in what manner the same may be used, what I claim as new and desire to protect by Letters Patent is:

1. In a log barker, a pair of trunnion wheel units forming a trough to support a log, means for rotating said trunnion wheels to turn the log, means to lower one of said trunnion wheel units relative to the other to roll the log out of one side of said trough, and means to roll a log into said trough from its opposite side whereby the log rolls against the trunnion wheels on said one side with an impact, said lowering means including a resilient shock absorber arranged to cushion said impact.

2. In a log barker as defined in claim 1, said lowering means comprising a piston in a cylinder.

3. In a log barker as defined in claim 1, said means to lower one of said trunnion wheel units comprising a pair of walking beams pivotally mounted intermediate their ends for rocking movement about a common axis, and bearings in the ends of said beams supporting said trunnion wheel units.

4. In a log barker as defined in claim 3, a fluid pressure cylinder and piston arranged to rock said beams.

5. In a log barker, log turning apparatus comprising a pair of parallel walking beams pivotaliy mounted intermediate their ends for rocking movement about a common axis, a pair of parallel horizontal trunnion wheel units mounted for rotation in bearings in the ends of said beams, said trunnion wheel units forming a trough to support the log, a drive shaft on said common axis arranged for rotating said trunnion wheel units to turn the log, an equalizing shaft having an arm extending under each of said beams, an approximately vertical link connecting each arm with one end of each beam, and a fluid pressure cylinder and piston unit connected with an arm on said shaft to rock the beams and roll the log out of said trough.

6. In a log barker, a pair of trunnion wheel units forming a trough to support and rotate the log, means to roll a log over one of said trunnion wheel units causing the log to impact against the other trunnion :wheel unit, means supporting said other trunnion wheel unit for vertical movement, and a shock absorber operable on said other trunnion wheel unit to cushion said impact.

7. In a log barker as defined in claim 6, said shock absorber comprising a fluid pressure piston and cylinder unit, said piston and cylinder unit being arranged to lower said other trunnion wheel unit for rolling the log out of said trough.

8. In a log barker, a pair of parallel walking beams pivotally mounted intermediate their ends for rocking movement about a common axis, a pair of parallel horizontal trunnion wheel units mounted for rotation in bearings in the ends of said beams, said trunnion wheel units forming a trough to support the log, means for rotating said trunnion Wheels to turn the log, resting pads under one end of said beams, and a fluid pressure cylinder having a piston acting in one direction to hold said beams against said pads, said piston being operable in the opposite direction to rock said beams ofi said pads and roll the log out of said trough.

9. A log barker comprising a pair of parallel trunnion wheel units forming a trough for supporting and turning a log, infeed conveyor means for rolling a log into one side of said trough, a rossing head mounted on a carriage for travel along a carriage way on the other side of said trough, walking beams supporting said trunnion wheel units in the opposite ends of the beams, pivotal supports for said beams intermediate the ends of the beams, means for rocking said walking beams on said pivotal supports to roll the log out of said other side of said trough, inclined stationary ramp sections arranged to support a rolling log across said carriage Way, and off-bearing conveyor means arranged to receive the rolling log at the lower end of said ramp sections.

References Cited by the Examiner UNITED STATES PATENTS 2,575,302 11/1951 Shaw.

2,600,625 6/1952 Ekholm etal.

WILLIAM W. DYER, 111., Primary Examiner.

W. D. BRAY, Assistant Examiner. 

1. IN A LOG BARKER, A PAIR OF TRUNNION WHEEL UNITS FORMING A TROUGH TO SUPPORT A LOG, MEANS FOR ROTATING SAID TRUNNION WHEELS TO TURN THE LOG, MEANS TO LOWER ONE OF SAID TRUNNION WHEEL UNITS RELATIVE TO THE OTHER TO ROLL THE LOG OUT OF ONE SIDE OF SAID TROUGH, AND MEANS TO ROLL A LOG INTO SAID TROUGH FROM ITS OPPOSITE SIDE WHEREBY THE LOG ROLLS AGAINST THE TRUNNION WHEELS ON SAID ONE SIDE WITH AN IMPACT, SAID LOWERING MEANS INCLUDING A RESILIENT SHOCK ABSORBER ARRANGED TO CUSHION SAID IMPACT. 